This source file includes following definitions.
- configfs_setattr
- set_default_inode_attr
- set_inode_attr
- configfs_new_inode
- configfs_set_inode_lock_class
- configfs_set_inode_lock_class
- configfs_create
- configfs_get_name
- configfs_drop_dentry
- configfs_hash_and_remove
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16 #undef DEBUG
17
18 #include <linux/pagemap.h>
19 #include <linux/namei.h>
20 #include <linux/backing-dev.h>
21 #include <linux/capability.h>
22 #include <linux/sched.h>
23 #include <linux/lockdep.h>
24 #include <linux/slab.h>
25
26 #include <linux/configfs.h>
27 #include "configfs_internal.h"
28
29 #ifdef CONFIG_LOCKDEP
30 static struct lock_class_key default_group_class[MAX_LOCK_DEPTH];
31 #endif
32
33 static const struct address_space_operations configfs_aops = {
34 .readpage = simple_readpage,
35 .write_begin = simple_write_begin,
36 .write_end = simple_write_end,
37 };
38
39 static const struct inode_operations configfs_inode_operations ={
40 .setattr = configfs_setattr,
41 };
42
43 int configfs_setattr(struct dentry * dentry, struct iattr * iattr)
44 {
45 struct inode * inode = d_inode(dentry);
46 struct configfs_dirent * sd = dentry->d_fsdata;
47 struct iattr * sd_iattr;
48 unsigned int ia_valid = iattr->ia_valid;
49 int error;
50
51 if (!sd)
52 return -EINVAL;
53
54 sd_iattr = sd->s_iattr;
55 if (!sd_iattr) {
56
57 sd_iattr = kzalloc(sizeof(struct iattr), GFP_KERNEL);
58 if (!sd_iattr)
59 return -ENOMEM;
60
61 sd_iattr->ia_mode = sd->s_mode;
62 sd_iattr->ia_uid = GLOBAL_ROOT_UID;
63 sd_iattr->ia_gid = GLOBAL_ROOT_GID;
64 sd_iattr->ia_atime = sd_iattr->ia_mtime =
65 sd_iattr->ia_ctime = current_time(inode);
66 sd->s_iattr = sd_iattr;
67 }
68
69
70 error = simple_setattr(dentry, iattr);
71 if (error)
72 return error;
73
74 if (ia_valid & ATTR_UID)
75 sd_iattr->ia_uid = iattr->ia_uid;
76 if (ia_valid & ATTR_GID)
77 sd_iattr->ia_gid = iattr->ia_gid;
78 if (ia_valid & ATTR_ATIME)
79 sd_iattr->ia_atime = iattr->ia_atime;
80 if (ia_valid & ATTR_MTIME)
81 sd_iattr->ia_mtime = iattr->ia_mtime;
82 if (ia_valid & ATTR_CTIME)
83 sd_iattr->ia_ctime = iattr->ia_ctime;
84 if (ia_valid & ATTR_MODE) {
85 umode_t mode = iattr->ia_mode;
86
87 if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
88 mode &= ~S_ISGID;
89 sd_iattr->ia_mode = sd->s_mode = mode;
90 }
91
92 return error;
93 }
94
95 static inline void set_default_inode_attr(struct inode * inode, umode_t mode)
96 {
97 inode->i_mode = mode;
98 inode->i_atime = inode->i_mtime =
99 inode->i_ctime = current_time(inode);
100 }
101
102 static inline void set_inode_attr(struct inode * inode, struct iattr * iattr)
103 {
104 inode->i_mode = iattr->ia_mode;
105 inode->i_uid = iattr->ia_uid;
106 inode->i_gid = iattr->ia_gid;
107 inode->i_atime = iattr->ia_atime;
108 inode->i_mtime = iattr->ia_mtime;
109 inode->i_ctime = iattr->ia_ctime;
110 }
111
112 struct inode *configfs_new_inode(umode_t mode, struct configfs_dirent *sd,
113 struct super_block *s)
114 {
115 struct inode * inode = new_inode(s);
116 if (inode) {
117 inode->i_ino = get_next_ino();
118 inode->i_mapping->a_ops = &configfs_aops;
119 inode->i_op = &configfs_inode_operations;
120
121 if (sd->s_iattr) {
122
123
124
125
126 set_inode_attr(inode, sd->s_iattr);
127 } else
128 set_default_inode_attr(inode, mode);
129 }
130 return inode;
131 }
132
133 #ifdef CONFIG_LOCKDEP
134
135 static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
136 struct inode *inode)
137 {
138 int depth = sd->s_depth;
139
140 if (depth > 0) {
141 if (depth <= ARRAY_SIZE(default_group_class)) {
142 lockdep_set_class(&inode->i_rwsem,
143 &default_group_class[depth - 1]);
144 } else {
145
146
147
148
149 pr_info("Too many levels of inodes for the locking correctness validator.\n");
150 pr_info("Spurious warnings may appear.\n");
151 }
152 }
153 }
154
155 #else
156
157 static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
158 struct inode *inode)
159 {
160 }
161
162 #endif
163
164 struct inode *configfs_create(struct dentry *dentry, umode_t mode)
165 {
166 struct inode *inode = NULL;
167 struct configfs_dirent *sd;
168 struct inode *p_inode;
169
170 if (!dentry)
171 return ERR_PTR(-ENOENT);
172
173 if (d_really_is_positive(dentry))
174 return ERR_PTR(-EEXIST);
175
176 sd = dentry->d_fsdata;
177 inode = configfs_new_inode(mode, sd, dentry->d_sb);
178 if (!inode)
179 return ERR_PTR(-ENOMEM);
180
181 p_inode = d_inode(dentry->d_parent);
182 p_inode->i_mtime = p_inode->i_ctime = current_time(p_inode);
183 configfs_set_inode_lock_class(sd, inode);
184 return inode;
185 }
186
187
188
189
190 const unsigned char * configfs_get_name(struct configfs_dirent *sd)
191 {
192 struct configfs_attribute *attr;
193
194 BUG_ON(!sd || !sd->s_element);
195
196
197 if (sd->s_type & (CONFIGFS_DIR | CONFIGFS_ITEM_LINK))
198 return sd->s_dentry->d_name.name;
199
200 if (sd->s_type & (CONFIGFS_ITEM_ATTR | CONFIGFS_ITEM_BIN_ATTR)) {
201 attr = sd->s_element;
202 return attr->ca_name;
203 }
204 return NULL;
205 }
206
207
208
209
210
211
212 void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent)
213 {
214 struct dentry * dentry = sd->s_dentry;
215
216 if (dentry) {
217 spin_lock(&dentry->d_lock);
218 if (simple_positive(dentry)) {
219 dget_dlock(dentry);
220 __d_drop(dentry);
221 spin_unlock(&dentry->d_lock);
222 simple_unlink(d_inode(parent), dentry);
223 } else
224 spin_unlock(&dentry->d_lock);
225 }
226 }
227
228 void configfs_hash_and_remove(struct dentry * dir, const char * name)
229 {
230 struct configfs_dirent * sd;
231 struct configfs_dirent * parent_sd = dir->d_fsdata;
232
233 if (d_really_is_negative(dir))
234
235 return;
236
237 inode_lock(d_inode(dir));
238 list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
239 if (!sd->s_element)
240 continue;
241 if (!strcmp(configfs_get_name(sd), name)) {
242 spin_lock(&configfs_dirent_lock);
243 list_del_init(&sd->s_sibling);
244 spin_unlock(&configfs_dirent_lock);
245 configfs_drop_dentry(sd, dir);
246 configfs_put(sd);
247 break;
248 }
249 }
250 inode_unlock(d_inode(dir));
251 }